1. Field of the Invention
The present invention relates generally to push-pull lock connectors and, more particularly, to a squared section, push-pull lock connector.
2. Description of the Prior Art
Japanese U.M. Patent Application Kokoku No. 53-25835 discloses an electrical connector which includes a cylindrical plug housing for housing contacts and having a locking projection for engagement with the locking portion of a mating connector; a cylindrical sliding sleeve fitted over the plug housing above the locking projection and movable for a predetermined distance defined by a stopper; and a coiled spring provided between the plug housing and the sliding sleeve.
To unlock the connector, the sliding sleeve is pulled upwardly against the coiled spring to disengage the locking projections. Under locking conditions, the sliding sleeve is biased downwardly by the coiled spring over the plug housing, thereby keeping the locking engagement.
However, for square sectioned plug housings, it is impossible to use the coiled spring which is wound around the cylindrical plug housing. It is very difficult to make square sectioned coiled springs. Even if made, they hardly stay square sectioned because of spring back effects. In addition, the coiled spring is not secured to the plug housing or the sliding sleeve so that it often that the coiled spring fall upon dissembling, resulting in the low productivity. These problems have hampered the manufacture of square sectioned push-pull lock connectors.